The 5th Tone...

This is a question about Mandarin as much as it is about Memrise--although the two are related. Is there a fully authoritative reference for tones in Mandarin? I understand that as a language there are regional deviations. However, Memrise as far as I can tell has no mechanism for alternate pinyin like they do for English and written Chinese. This comes up because sometimes two-character words cause the second character to take on the 5th tone, when it doesn't as a single character. When spoken, these ambiguities are almost imperceptible. However, in the harsh light of Memrise testing, the system forces one to memorize it--and I wonder if that's a waste of time since the goal (presumably) is actually learning Chinese.

This is a good point - the convention that we follow, which has not yet been totally universally applied, is that in the pronunciation field the "dictionary" version should be written first - that is the version with the correct tone for each individual character. Then a semi colon, and then the spoken version, if it is different. This is also very important for cases where other tones change when put into combination. If you do come across cases where the "dictionary" form is not accepted, please start a discussion on that word pointing out the issue and we will fix it at once,

Followup question: Does the PRC have an official dictionary? English dictionaries and domestic translation dictionaries are probably subject to copyright, which is possibly why you didn't name the specific one you refer to. If the PRC can simplify how a language is written, could they not specify how it is spoken? Again, I don't want to start a 'discussion' if there's already a correct answer.

Another good question - I don't think that there is an "official" dictionary; not one that I have ever heard of at least. But I will check. There are a bunch of very widely used ones.

Sorry not to be clear - I wasn't in fact referring to a particular dictionary, but to the general convention in dictionaries to specify pronunciation according to the correct tones of each character, rather than to try to represent the tones as they are spoken. This is why I call that the "dictionary" version.

I think that they do this partly for simplicity of writing the entries, and partly for simplicity when looking up: the characters are listed in the order of the tones within each pronunciation, and this would be made extra painful if you had to work out whether they were applying the tone-change rules as well.

With regards to the government specifying how words are spoken; I think that that realise that they would be on a bit of a hiding to nowhere trying to do that!